Electrodialysis for RO Concentrate Management in Steel Wastewater ZLD

Steel production generates complex, high-salinity wastewater streams. As water reuse and zero-liquid-discharge requirements become increasingly important, the treatment of RO concentrate has become a key challenge—particularly when the concentrate must ultimately be handled by energy-intensive evaporation processes.

In the Yunnan Shenlong Steel Wastewater Zero Liquid Discharge Project, LANRAN’s electrodialysis system is integrated downstream of the secondary RO process to further concentrate the RO concentrate before final evaporation.

At the same time, the dilute stream produced by electrodialysis is returned to the upstream RO process for further treatment and water recovery.

Secondary RO Concentrate → Electrodialysis → Concentrate → Final Evaporation

　　　　　　　　　　　　　　　　　 ↘ Dilute Stream → RO Process

By introducing electrodialysis as an intermediate concentration step, the process helps reduce the water volume entering the final evaporation stage while maintaining water within the treatment loop.

The system was installed, commissioned, and put into production in July 2026.

This project demonstrates how ED can be integrated with RO and evaporation to optimize high-salinity wastewater treatment and support ZLD in the steel industry.